Re: [PATCH 03/10] i2c: i801: Make p2sb_spinlock a mutex

[Jean Delvare <jdelvare@suse.de>]

On Sun, 01 Aug 2021 16:18:38 +0200, Heiner Kallweit wrote:
> p2sb_spinlock is used in i801_add_tco_spt() only and in process context
> only. Therefore a mutex is sufficient, and we can make the definition
> local to i801_add_tco_spt().

Mika, no objection?

> Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
> ---
>  drivers/i2c/busses/i2c-i801.c | 7 +++----
>  1 file changed, 3 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-i801.c
> index bdb619bc0..504f02e1e 100644
> --- a/drivers/i2c/busses/i2c-i801.c
> +++ b/drivers/i2c/busses/i2c-i801.c
> @@ -1492,12 +1492,11 @@ static const struct itco_wdt_platform_data spt_tco_platform_data = {
>  	.version = 4,
>  };
>  
> -static DEFINE_SPINLOCK(p2sb_spinlock);
> -
>  static struct platform_device *
>  i801_add_tco_spt(struct i801_priv *priv, struct pci_dev *pci_dev,
>  		 struct resource *tco_res)
>  {
> +	static DEFINE_MUTEX(p2sb_mutex);

To be on the safe side, we should explicitly #include <linux/mutex.h>.

>  	struct resource *res;
>  	unsigned int devfn;
>  	u64 base64_addr;
> @@ -1510,7 +1509,7 @@ i801_add_tco_spt(struct i801_priv *priv, struct pci_dev *pci_dev,
>  	 * enumerated by the PCI subsystem, so we need to unhide/hide it
>  	 * to lookup the P2SB BAR.
>  	 */
> -	spin_lock(&p2sb_spinlock);
> +	mutex_lock(&p2sb_mutex);
>  
>  	devfn = PCI_DEVFN(PCI_SLOT(pci_dev->devfn), 1);
>  
> @@ -1528,7 +1527,7 @@ i801_add_tco_spt(struct i801_priv *priv, struct pci_dev *pci_dev,
>  	/* Hide the P2SB device, if it was hidden before */
>  	if (hidden)
>  		pci_bus_write_config_byte(pci_dev->bus, devfn, 0xe1, hidden);
> -	spin_unlock(&p2sb_spinlock);
> +	mutex_unlock(&p2sb_mutex);
>  
>  	res = &tco_res[1];
>  	if (pci_dev->device == PCI_DEVICE_ID_INTEL_DNV_SMBUS)

Reviewed-by: Jean Delvare <jdelvare@suse.de>

-- 
Jean Delvare
SUSE L3 Support